issue with case fan speed settings

Hey OC'ers,

One of my fans (Scythe Slipstream SY1225SL12SH) currently spins at less than full speed for several seconds and then stops completely, alternating between these two. In the BIOS it shows cha_2 (which this fan is currently connected to) level 4 (with options ranging from 1-4) but other other chassis fan settings allow me to set to full power. Any advice on what to do? Thanks in advance!




Edit
I've also just now tried this fan in the power fan 1 header and it's gone from 200 rpm slowly up to 170 rpm over the course of the past few minutes

update
The fan continues to alternate between 500's and 0 rpm

update 2
I've the fan with an identical one and it seems to be running better now. Speedfan shows a solid ~1900 RPM. I opened up the problematic fan and it looks like there was a it of dried up clumps of lubricant and after putting the fan back together there's a bit of resistance while spinning it by hand. Any advice as to what I could use? Vaseline perhaps?

A drop of motor oil (either automotive or electric machine) will work. Or just replace it.

Thank you mike, I might have something in the garage. Hopefully it will do the trick as it'll be nice to maintain my stock of them